the websocket benchmark client via the WebSocket-Node

readme.txt

Intro:
About the `WebSocket-Node' part please refer https://github.com/Worlize/WebSocket-Node for details.

The above client part wants to roughly test the max concurrency connections of the websocket server, loop send UTF content to server and broadcast its updates to 
other connected clients.

Issue:
Since i don't find any up-to-date websocket testing tool like "ab or siege", I am using the "&"(node ./wsclient_test.js &) to mock the concurrence processes, but after i 
execute the first time test command ("sh ./test.sh"), i will find that there won't be able to setup the expected number of the node processes, 
the catched error is "Connect Error: Error: connect ETIMEDOUT", meanwhile the client and server's CPU is not 100% consumed, and the memory still have many available,
i try to run many times test shell(sh ./test.sh) and there will some new connections are established, but the "ETIMEDOUT" is frequently happened.

The testing client and the server are two machines in LAN, (Pentium(R) Dual-Core  CPU E5300 @ 2.60GHz, 8G RAM, x86_64 GNU/Linux), the "ulimit" settings as following:
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 60803
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 65535
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 60803
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

node version:v0.6.19
WebSocket-Node version:1.0.6

I am a newbie about the "ws" benchmark, could you please kindly advice any ideas how can i do the benchmark for the concurrency connections(aviod the "ETIMEDOUT" issue
as much as possible)?

So far, the server supports 2651 clients(this number maybe can be increased, if i try to renew more executions for the "sh ./test.sh")
Server:
Cpu(s): 42.4%us,  4.2%sy,  0.0%ni, 49.5%id,  0.0%wa,  0.0%hi,  3.8%si,  0.2%st
Client:
Cpu(s): 29.3%us,  7.0%sy,  0.0%ni, 63.2%id,  0.0%wa,  0.0%hi,  0.2%si,  0.3%st

Thanks in advance!

test.sh

#!/bin/bash

x=1
while [ $x -le 30 ]
do
    echo "start $x instance"
    node ./wsclient_test.js &
    x=$(( $x + 1 ))
done

wsclient_test.js

#!/usr/bin/env node

function start_one_client() {

    var WebSocketClient = require('websocket').client;

    var client = new WebSocketClient();
    var _id = new Date().getTime();

    client.on('connectFailed', function(error) {
        console.log('Connect Error: ' + error.toString());
    });

    client.on('connect', function(connection) {
        console.log('WebSocket client connected');

        connection.on('error', function(error) {
            console.log("Connection Error: " + error.toString());
        });

        connection.on('close', function() {
            console.log('online protocol Connection Closed');
        });
        
        connection.on('message', function(message) {
            if (message.type === 'utf8') {
                console.log("Received: '" + message.utf8Data + "'");
            }
        });

        function sendNumber() {
            if (connection.connected) {
                var a = parseInt(Math.random()*100+1);
                var b = parseInt(Math.random()*100+1);
                msg = {sns_id:_id, data:{x:a, y:b}}
                connection.sendUTF(JSON.stringify(msg));
                setTimeout(sendNumber, 10000);
            }
        }
        sendNumber();
    });

    client.connect('ws://host:8084/online');
}

for(var i=0;i<100;i++){
    console.log("start " + i + " websocket client");
    start_one_client();
}